diff --git a/src/mami.js/utility.js b/src/mami.js/utility.js
index de155d2..393581f 100644
--- a/src/mami.js/utility.js
+++ b/src/mami.js/utility.js
@@ -208,7 +208,7 @@ const $x = (function() {
             if(body instanceof URLSearchParams) {
                 requestHeaders.set('content-type', 'application/x-www-form-urlencoded');
             } else if(body instanceof FormData) {
-                requestHeaders.set('content-type', 'multipart/form-data');
+                // content-type is implicitly set
             } else if(body instanceof Blob || body instanceof ArrayBuffer || body instanceof DataView) {
                 if(!requestHeaders.has('content-type'))
                     requestHeaders.set('content-type', 'application/octet-stream');